Rotary engine



(No Model.) a Sheets-Sheet 1.

G. H. GRAHAM.

I ROTARY ENGINE. No. 494,138. Patented Mar. 28, 1893.

llllllllllllllllllllllllllllll ll Witmeoom UNITED STATES PATENT OFFICE.

GEORGE H. GRAHAM, OF RIDGELAND, ILLINOIS.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 494,138, dated March28, 1893.

Application filed April 18,1892. Serial No. 429,637. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE H. GRAHAM, a citizen of the United States,residing at Ridgeland, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Rotary Engines; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

This invention relates to rotary engines; and has for its object toprovide a compound or double expansion rotary engine, which will besimple in construction, eflicient, and utilize the double expansiveforce of the steam to the best possible advantage.

A further purpose of the invention is the provision of instrumentalitiesfor conven iently altering the force of resistance of the governor tochange the speed of the engine, said instrumentalities being locatedwithin the piston and operated through an opening in the head of thecasing which opening is closed by a screw plug or other convenient meansof closure.

Astill further purpose and the primary object of the invention is theimprovement of the general construction of this class of engines,whereby their usefulness and efficiency are increased to an eminentdegree.

The improvement consists of the novel features and the peculiarconstruction and combination of the parts which will be hereinafter morefully described and claimed and which are shown in the annexed drawings,in which;

Figure 1 is a side elevation of an engine embodying myinvention, partsbeing broken away to show the roller valve and itscasing. Fig. 2 is asection about on the lineXX of Fig. 1 looking to the right, showing thesteam inlet and exhaust ports in the piston in full. Fig. 3 is a frontView of a valve casing and the mechanism for controlling the valve,showing the relation of the same to the cylinder of the engine. Fig. 4is a side elevation of the piston, the cap plate being removed, showingthe governor. Fig. 5 is a detail view of the primary head of the pistonon a larger scale. Fig. 6 is a detail view of the governor settingmechanism. Fig. 7 is a detail View of the roller valve and its casing.Figs. 8, 9 and 10 are diagrammatical views, showing the relation of thevalves and the piston heads.

The cylinder 6 mounted on the bed or base 7 is closed at its ends by theheads 8 and. 9 which are centrally apertured to receive the shaft 5 towhich the piston 10 is secured and to which the balance wheels 11 arefastened. The bearings K for the shaft 5 are bolted to the cylinderheads and may be of any desired form. The packing L confined between thebearings and the said heads, prevents leakage of steam. The steam inletpassage H is formed in the head 9 and communicates with an annularchamber h on the inner side of the head and surrounding the shaft 5. Thesteam exhaust passage J provided in the head 8 communicates with theannular chamber j formed in the inner side of the said head andsurrounding the shaft 5. The steam inlet passage A in the pistoncommunicates with the annular chamber h and extends through the primaryhead a of the piston. The exhaust passage 0 leading into the annularchamber j extends through the peripheral surface of the piston just inthe rear of the primary piston head. The secondary piston head b located diametrically opposite the primary piston head a is constructed topresent considerable more surface for the action of the steam than theprimary piston head, being deeper. A passage B formed tangentiallythrough the piston extends through the head I) and through the peripheryof the piston just in the rear of the said head. The steam after itsprimary expansion, escapes through the said passage B to be expanded asecond time.

The cylinder is provided with four radially disposed valves which aredisposed at an equal distance apart around the said cylinder, and whichare adapted to slide within casings 12 bolted to or otherwise providedon the said cylinder. The valve heads 13 are recessed on their innerfaces to receive rollers 16 which are designed to travel on the pistonand relieve friction, and with a slot in one side in which is fitted apacking strip 15, the same preservinga close joint between the valve andpiston. The outer face of the head 13 is de pressed to receive a plate14 which overlaps the outer portion of the packing strip 15 and which isheld down at one edge by a scarf joint and bolted to the head at theother edge. The valve stem 17 passes through the plate and screws intothe valve head, having a shoulder just above the plate 14 to restthereon and assist in securing the said plate. The valve head fitssnugly within the casing 12 and to equalize the outward pressure on theinner face thereof, passages V are provided in one side of the casingfor the escape of steam to the outer side of the said valve head. Thisconstruction admits of the valve head being essentiallyabalanced valve.A lever A is pivotally connected between its ends to the head B of thevalve stem 17, and its ends has a spring connection with the cylinderheads. The heads have lugs 0 near their periphery, through which rods Dare inserted and secured at their inner ends by being screwed into thehub portions of the said heads. Heads E are mounted to slide on theserods and are connected with the ends of the lever A by rods F F whichpass through suitable openings in the lugs G. The springs d mounted onthe rods and confined between the lugs G and the heads E press the saidheads E toward the center of the cylinder and through the rods F F drawthe levers A in and press the valves close against the piston. A packingstrip T is inserted in a channel just in the rear of a piston head andis held therein by binding screw W. The front edge of this stripprojects sufficiently far in front of the piston head to preserve asteam tight joint between the piston and the cylinder. A packing orcushion S is provided in the depressed portion of the piston front ofthe piston heads to receive the blow of the valve and prevent noise andunnecessary wear. The valve the instant it leaves the head, strikes thepiston in front of the said head a smart blow. The cushion is providedto relieve the force of the blow. The packing may be of any suitablematerial and may be laminated orin one piece and is secured to thepiston in any convenient manner, preferably by being sprung into arecess formed therein and having under cut edges. The piston is hollowbeing open on one side which side is closed by a removable cap 19 whichis bolted thereto, and receives the governor and the mechanism forsetting the governor to control'the speed of the engine.

The gate K for controlling the inlet port A is connected with a bellcrank lever J, which is connected with the long arm of the equalizinglever H by connecting rod I which is adjustable to change the relationof the gate or cut off K to the port A. The weighted levers F and Fapproximately parallel with each other and with the equalizing lever11', are pivoted at diametrically opposite points and extend in oppositedirections on each side of the shaft 5 and are connected with theequalizing lever by the links L and G, respectively. The spring M forcontrolling the action of the governor, is connected at one end for thesake of convenience to the weighted lever F and at its other end to ahead N which is adapted to slide between parallel ribs X. A threaded rodQ is connected with the head N and passes through two lugs r 1" betweenwhich is confined a nut P threaded to correspond with the thread of thesaid rod Q on which it is mounted, and having a worm gear to mesh withthe worm shaft 0 which is parallel with the shaft 5. The outer end ofthe worm shaft 0 is countersunk in the cap plate 19 so as to come flushtherewith and is constructed to be engaged by a suitable instrument tobe rotated thereby to turn the nut P and move the rod Q in its bearingsso as to increase or diminish the tension of the spring M. The head 9 isprovided with an opening opposite the worm shaft 0 which is closed by ascrew plug 20 to admitof access to the said shaft for changing the forceof resistance of the governor. After the governor has been properlyregulated the engine will run at a uniform speed. As the free orweighted ends of the levers F and F fly out the cut off will beprojected across the steam port A and shut off the steam and as theymove toward the center the cut off will be withdrawn so as to open theport A wider and admit more steam to the engine. The live steam enterspassage H, annular chamber h and passes through the passage A into thecylinder.

Suppose the valves 1, 2, 3 and 4 and the piston to be in the positionshown in Fig. 8, the steam entering through port A exerts its expansiveforce against valve 2 and the primary piston head a. As the pistonrevolves, see Fig. 9 which shows the valves 1 and 3 partly closed forthe sake of better illustrating the application of the invention, thehigh pressure is partly against valve 2 and the said valve 3, while thesteam is expanding a second time between the secondary piston head I)and the valves 4 and 1. When the piston reaches the position shown inFig. 10 valves 1 and 3 are entirely closed, and the primary expansion isagainst 3 and secondary against valve 1, while between valves 2 and 3 isinclosed steam once expanded and between valves 1 and t steam twiceexpanded. On a farther rotation of the piston, the primary expansion isstill against valve 3, while the once expanded steam from between valves2 and 3 escapes through passage B and acts against valve 1 and thesecondary piston head, while the twice expanded steam inclosed betweenvalves 1 and 4 escapes through the exhaust port 0.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. In a rotary engine, the combination with the casing, a hollow pistonlocated withinsaid casing, and having one side arranged to work steamtight against a head of the said casing, and a governor located withinthe said piston, of a governor controlling mechanism located within thesaid piston and adapted to be reached through co-incident openings inthe said steam tight fitting side of the piston and the head of thecasing, and a plug for closing the opening in the head of the casing,substantially as described.

2. In a rotary engine, the combination with the casing having a lateralopening in one of its heads, a hollow piston having one side open, andhaving the open side closed by a cap plate, said piston fitting steamtight between .the heads of the casingand having an opening in said capplate to register with a corresponding opening in a head of the casing,of a governor and a governor controlling mechanism located within saidpiston and the governor controlling mechanism adapted to be actuatedthrough the said co-incident openings,and a plug for closing the openingin the casing head, substantially as described.

3. In a rotary engine, the combination with a casing, a hollow pistonarranged to work in the said casing, and a governor placed within saidhollow piston, of a spring connected at one end with the governor, ahead connected with the other end of the spring and working in guides,and a mechanism for moving said head in the guides to vary the tensionon the said spring adapted to be actuated through co-incident openingsin a side of the piston and a head of the casing, substantially as setforth.

4:. In a rotary engine, the combination with a hollow piston, and agovernor located Within the said piston,of a spring connected with thegovernor, a threaded rod attached to the said spring, a nut mounted onthe said threaded rod and having a worm gear, and a worm threaded shaftto rotate the said nut to vary the tension of the said spring,substantially as and for the purpose described.

5. In a rotary engine, the combination with.

a piston having a steam inlet port A formed therein, and a cut off tocontrol the said port, of weighted levers, one on each side of theaxis'of the piston, an equalizing lever connected with the said weightedlevers, and connections between the said cut off and the said equalizinglever, substantially as described.

6. In a rotary engine, the combination with a piston having a steaminlet port A formed therein, and a cut off to control the said port, ofweighted levers, one on each side of the axis of the piston, anequalizing lever, the three levers being approximately parallel andlinks connecting the Weighted levers with the equalizing lever, a bellcrank lever connected with the out off and an adjustable connecting rodbetween the said bell crank lever and the equalizing lever,substantially as described.

7. In a rotary engine, the combination with a piston having a steaminlet port A formed therein, and a cut off to control the said port, ofweighted levers, one on each side of the axis of the piston, anequalizing lever, the three levers being approximately parallel andlinks connecting the weighted levers with the equalizing lever, a bellcrank lever connected with the cut off, an adjustable connecting rodbetween the said bell crank lever and the equalizing lever, a springconnected at one end with one of the weighted levers, and a tensioncontrollingmechanism connected with the other end of the said spring,substantially as described. 7

8. In a rotary engine, the combination with a cylinder, and four valvesequally disposed around the same, of a piston having a primary and asecondary head to use the expansive force of the steam twice, thesecondary piston head being of larger area than the primary piston headto admit of the once used steam exerting a force on the said secondarypiston head about equal to that exerted in the first instance on theprimary piston head.

9. In a rotary engine, the combination with a piston having a primaryand a secondary piston head, a steam passage being formed through thesaid secondary piston head, of a cylinder, and four valves equallydisposed around the said cylinder, substantially as described.

10. In a rotary engine, the combination with a piston having a primaryand a secondary piston head, a steam passage being formed through thesaid secondary piston head, the steam inlet port extending through theprimary piston head, and having the exhaust port leading through thepiston just in the rear of the said primary piston head, of a cylinderand four valves equally disposed around the said cylinder, substantiallyas described.

11. In a rotary engine, the combination with the cylinder having acasing, of a valve head 13 having a slot in one side and provided with aroller on its inner face, and having a depression in its outer face, apacking strip 15 inserted in the said slot, and a plate 14:

fitted in the said depression and bearingdown on the upper edge of thesaid strip 15, substantially as and for the purpose specified.

12. In arotary engine, the combination with the cylinder having a valvecasing, a radially working valve located in and having its stem Workingthrough thevalve casing, and radial guide rods D exterior to andsupported by the cylinder heads, of a lever A pivoted midway of its endsto the said valve stem, rods F connected at their outer ends with theends of the pivoted lever A and guided in their movements by lugs on thesides of the cylinder heads, cross heads E mounted to slide on the rodsD and connected with the inner ends of the rods F, and springs 01mounted on the rods D and held between the said cross heads and thelugs, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE E. GRAHAM.

Witnesses:

FRANCIS L. GRAHAM, HERMAN HAAs.

